


Potion Brewing for Dummies

by EmeraldOre (Raayner)



Series: Polytechs Smut [2]
Category: Hermitcraft RPF
Genre: Aftercare, Anal Sex, Begging, Biting, Breast Fucking, Cunnilingus, Dom/sub, Double Penetration, Exactly What It Says on the Tin, Explicit Consent, Gender or Sex Swap, Grian with a vagina, M/M, Misuse of Potions, Multiple Orgasms, Nipple Play, Overstimulation, Plot What Plot/Porn Without Plot, Self-Indulgent, Threesome - M/M/M, Transformation, Vaginal Fingering, Vaginal Sex, polytechs - Freeform
Language: English
Status: Completed
Published: 2020-04-16
Updated: 2020-04-16
Packaged: 2021-03-02 01:29:10
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,080
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23606833
Author URL: https://archiveofourown.org/users/Raayner/pseuds/EmeraldOre
Summary: When brewing a potion to get back at his boyfriends, Grian experiences some side-effects he did not anticipate.Not one to look a gift-horse in the mouth, he decides to roll with it and have a good time.
Relationships: Grian/Mumbo Jumbo/Iskall85
Series: Polytechs Smut [2]
Series URL: https://archiveofourown.org/series/1728073
Comments: 12
Kudos: 194





	Potion Brewing for Dummies

**Author's Note:**

> PLEASE HEED THE TAGS  
> This is a very self-indulgent fic and if there is anything that doesn't appeal to you then do not read it.  
> TLDR: grian brews a potion that gives him boobs and a vagina, then Mumbo and Iskall fuck him.
> 
> I had fun writing this, I hope you enjoy a little over 4k words of smut~
> 
> This is technically a sequel to my fic Private Concert but can be read by itself. There's not really any plot to follow lol

So, Grian had fucked up.

Not in some big, threw a potato in Sahara way - just a little confusion with potion ingredients, really. 

How was he supposed to know that an extra pinch of blaze powder would be too much? It wasn’t like there was a guide for these things or else he would have used it! Making new potion effects was a matter of trial and error, afterall. He was lucky it was only a little too strong and hadn’t hurt him. 

Grian had wanted to get back at his boyfriends for the little ‘private show’ he’d given at the end of last season - and maybe get reacquainted with each other in their new homes after the move, since they had all been so busy setting up their bases. If their reaction to his Ariana Grian-de outfit had been that good, he wondered what they would do if he  _ actually _ had tits they could touch. 

After brewing up a couple standard stamina potions, he had set about experimenting on a potion that could change his physical form. It took a while, but he finally found a recipe that would do the trick. And then… he had added the extra blaze powder. 

It wasn’t terrible, he supposed, running his hands experimentally over his new breasts, down his stomach, over his slightly wider hips, and dipped between his thighs. The absence was weird, he decided, but he liked how it felt; how sensitive everything was! Having a vagina hadn’t been a part of the plan, but he could work with this. 

Grian tentatively played with the folds for a minute, getting used to the new sensations. He gasped when his fingers touched his clit, the feeling much too sharp. He frowned, adjusting his approach, and felt his knees shake at the wave of pleasure that rolled through him. 

He rubbed tentatively, slowly finding a rhythm that worked, the hot feeling in his groin building and building until a shout burst from his mouth, orgasm catching him by surprise. He panted for breath, legs quivering and blood pounding.  _ That _ was an entirely new experience. He dipped a finger lower, not quite inside, but enough to feel and marvel at the wetness there. 

Well  _ damn _ . He could get behind this. 

After a few more minutes his body started to tingle, the sip he’d had wearing off. His skin itched fiercely as his body returned to its original shape, but nothing hurt, so this potion was successful.

Grian eyed the remaining liquid, doing some quick math in his head. While unexpected, the effects of his new potion could be accounted for in his plan, he just had to adjust a few things.

Oh yes, wouldn’t Mumbo and Iskall be surprised.

\- - -

A couple of days later, he put his plan into action.

Grian opened his, Mumbo, and Iskall’s private chat and sent a message asking if they were available to meet him at his base. He re-checked his supplies and smoothed out his sheets, adjusting the loose cloth robe he was wearing. 

His communicator dinged, showing a message from Iskall, then Mumbo, that they would be over in a few minutes. He quickly gulped down his special potion, resisting the urge to scratch as his skin grew and stretched. After making sure he was still presentable, he waited around the corner from the entrance of his base, listening. Soon enough, he heard the whistle of wind through twin elytras and the murmur of his boyfriend’s voices. 

“Grian,” he heard Iskall call, “where is my lovely boyfriend?”

“ _ Our _ boyfriend,” Mumbo stressed, sputtering when Grian assumed Iskall elbowed him.

“He’s  _ my _ lovely boyfriend, he’s  _ your _ cute one,” Iskall explained, “together, he’s the ultimate lover.” 

Grian covered his mouth as he tried not to laugh along with them, his heart swelling with love. He cleared his throat and called out to them.

“In here you two!”

As he heard them step in he pushed off from the wall, turning to face them. He watched as Iskall’s grin froze on his face, his eyes widening as he took in Grian’s robe, and the odd shape of his body beneath. Mumbo looked between them for a moment before he too took notice of how different Grian looked.

“Grian?” Mumbo asked, concerned.

“Hey guys,” he said, “I feel bad we haven’t been able to see each other as much, so I thought I’d make a little… surprise for the three of us to enjoy?”

“Grian, wha -” he hurried to cut Iskall off.

“I know how much you loved Ariana Grian-de,” he winked, “but maybe you could do with little ol’ me?”

He loosened the tie around his waist, shrugging the robe off his shoulders and letting it drop at his feet.

Iskall’s jaw  _ dropped _ . Mumbo looked like he was going to pass out from the amount of blood that had rushed to his face, and Iskall actually got on his knees and started praying.

“I take it you approve?” Grian asked with a laugh.

“Grian! What did you - what?” Mumbo blustered over the sound of Iskall’s praises to - what sounded like - made up deities, “are you okay? Is this safe?”

“Oh my Mumbo,” Grian stepped forward and ran a finger up the mustached man’s tie, “I’m perfectly safe - from the potion anyway.”

Mumbo’s voice caught in his throat, enchanted by the image before him. Grian smirked, taking a step back and reaching into a chest. He handed one of the stamina potions to him, then dangled the other in Iskall’s face.

“Drink up, then join me in the bedroom.”

He didn’t stick around to see if they did, but he heard the pop of the corks. He sat on the edge of his mattress, crossing his legs (and wow, was that so much easier without a dick) and waited for the others. They appeared, bulges already noticeable in their pants. Mumbo’s face was still flushed and Iskall’s eyes were slightly wild, laser-focused on Grian’s breasts.

Grian quirked an eyebrow at him, gesturing for him to come forward. Iskall hesitated, sharing a look with Mumbo.

“Guys, what’s up?”

“Grian,” Iskall said, looking back at him, “we want to make sure we know what’s okay, here. This is pretty uhhh new, sweetheart.” Mumbo nodded, chewing at his lip.

Grian sighed, beckoning them forward so he could take a hand in each of his. He looked up at his boyfriends, squeezing reassuringly.

“I just want a fun day with my boyfriends - with a little payback for ruining my outfit last time,” they shared a laugh at that, the mood lightening significantly, “I’m good for  _ whatever _ , as usual. I’m yours to do with what you will, and I’ll safeword out if it gets too much, okay?”

“Same Grian, different fun bits?” Iskall asked with a grin, to which Grian responded with his own. 

“Exactly. We good, Mumbo?”

“Peachy! Just was a little worried, is all. I love you?”

“I love you too, you dorks!”

They all shared a smile, then Grian was gasping as hands covered his breasts and squeezed. He shot a look up at Iskall who was bent forward, cupping them with reverence.

“Thank you for this gift, Grian,” he said, “I’ll cherish them forever.”

Iskall pushed, toppling Grian onto his back, and kneeled beside him, rhythmically squeezing his hands the entire time. Grian groaned, pushing his chest up into the touch. It was much more sensitive than last time - he wasn’t sure if that was a side effect of the potion or just his body, though he didn’t actually care that much. 

“Mm,” he moaned, grasping at Iskall’s shoulder.

Fingers ran tentatively up and down his thigh, and he glanced down to see Mumbo sitting next to him, expression still kind of hesitant. 

Grian opened his mouth to say something when he gasped, head falling back against the sheets as pleasure shocked through him. He looked to see Iskall with an expression like a cat that had caught a mouse, having just brushed over his nipples.

“I see,” he purred, “you like that?”

He was unable to answer as the hardening nubs were flicked, voice calling out as he felt his crotch growing warmer. His thighs squeezed together, Mumbo’s fingers getting trapped between them briefly. 

“I liked your tits before, but man. They are beautiful. Not too big for my hands, and you’re so responsive,” Iskall bent down and kissed along his chest, palming his breasts and kneading them slowly. 

Grian mewled at the attention, reaching out for Mumbo desperately. He felt fingers grasp his own and he clutched at them, tugging the other man closer while Iskall ravaged his neck with nips and licks.

“Mumbo,” he gasped, “Mumbo I’m so  _ wet _ .”

He felt both of them stutter to a stop for a second, and then Iskall’s mouth covered his own while his hands worked double-time. He moaned into the kiss, spreading his thighs as he felt a hand run from his knee to his hip. Grian heard Mumbo suck in a breath and then a hand was smoothing over the rough hair of his mound. 

Mumbo’s hand crept experimentally along his folds, pressing down softly and finding him slick and wanting, the base of his thighs already messy with his arousal. A finger ran up the length of his slit and his toes curled, clit aching for some attention. 

Grian managed to pull his lips away from Iskall, his other boyfriend taking that moment to suck a hickey high on his neck and pinch cruelly at his nipples.

“AH,” he shouted, back bowing off the bed.

The mattress dipped as Mumbo slid off, but Grian’s complaints at that were cut off when strong hands lifted his legs and he felt shoulders slide under his knees. He tucked his face into his elbow as fingers spread his lips, blushing fiercely at the attention. 

Cool breath on heated skin was the only warning he had before a tongue was licking him open, tasting him from the source. Grian’s high pitched squeal broke into a moan when Mumbo curled his tongue, flicking up to his clit to play around it for a second before his lips wrapped around it, sucking. He pulled back briefly for a breath and then returned, exploring Grian with his mouth. Mumbo licked and sucked along his folds, occasionally pressing hot kisses to his clit to hear Grian cry out.

Grian could hear Iskall chuckle, but was too distracted by the wet sounds coming from below, somehow more obscene than any blowjob had been. 

Distracted, that was, until both of his nipples were pinched and tugged. He gasped, hips twitching up into Mumbo’s mouth. He uncovered his face to glare at Iskall, who smiled at him innocently.

“Are you liking that,” Iskall asked, “Mumbo on his knees for you, eating you out so good?”

Grian’s breath caught in his throat as he felt Mumbo’s tongue curl into him, fucking him with it. One of his breasts was suddenly caught in a mouth, and he shouted as Iskall bit at a nipple. 

He was caught between them, slick sounds and small, soft moans from Mumbo filling the air. 

After a few minutes of this, Iskall’s other hand left his chest and Grian felt Mumbo jerk back. Looking down, he could see fingers tangled in Mumbo’s hair, holding his head still. Iskall pulled off of his breast with a pop.

“Now Mumbo,” he said, “Grian’s been such a good boy for us - giving us all these fun new bits to play with - I think he deserves a reward. Stop  _ playing _ around in his cunt,” Iskall growled, “and make him cum.”

He felt arousal flood through him and his head fell back, mouth open, as Mumbo’s mouth returned with a vengeance. He focused on his clit, rolling and flicking his tongue around it until he found a pattern that made Grian scream, louder and louder as his climax grew. 

The pleasure crested, hovering at its peak, until a well-timed nip from Iskall sent him over the edge, orgasm crashing through him. He gasped in a ragged breath, chest heaving as his muscles tensed and then relaxed, arms falling boneless to his sides. 

Mumbo… had not stopped licking at him. Grian whined, squirming at the sensation of too much, post-orgasm glow fading into pain. 

“M-Mumbo! Mumbo stop,” he cried, “yellow!”

Immediately, the other man pulled off and two pairs of hands rested on him, petting soothingly. Grian blinked up to see his boyfriends looking at him with concern, Mumbo’s hair sticking up all over the place and mustache a mess. Iskall was more put together, but they were both frowning, worried.

“I’m okay,” Grian reassured them, reaching out to take their hands, “too sensitive. Need a bit before touching me there again is all.” 

He smiled up at them, squeezing Mumbo’s hand when he looked guilty. 

“Besides, I know a few things I can do while we wait,” Grian said, winking.

He sat up, tugging Mumbo onto the bed and pushing him towards Iskall who smirked, understanding what Grian wanted. 

“C’mere,” Iskall murmured, cupping Mumbo’s jaw. 

He brought their lips together, tilting Mumbo’s head for better access to his mouth. Iskall hummed, stroking Mumbo’s cheek, and Grian watched his other hand creep down the others back and grab his ass. Iskall pulled Mumbo down to lay on his back, laughing. 

“Grian, you taste amazing in his mouth,” he pulled back enough to say before continuing their kiss.

Grian chuckled, watching his boyfriends make out in his bed while he took a moment for himself. He just breathed for a while, feeling his heart slow its frantic pace of a minute ago, his body relaxing. Honestly, he could almost fall asleep if it weren’t for his desire to keep this party going. His eyes closed as he tried to think of what to do next. 

He heard rustling and a choked moan from Mumbo, and he looked up to see Iskall had pulled Mumbo’s pants off and was slowly jerking his cock. Grian grinned and started crawling towards them. 

Iskall looked up when he touched his arm, questioning. Grian pointed at Mumbo, then at his boobs while he pushed them together. Iskall nodded, reaching into his pocket and pulling out a small bottle of lube which he poured into a hand before slicking Mumbo’s dick. The mustached man looked at the two of them and rolled his eyes.

“Do you just carry lube with you everywhere?” he asked, voice a little wobbly at the touch.

“Usually,” Iskall agreed, “you never know when you might need to pull your boyfriend into a shop and fuck him, y’know.”

Grian smiled fondly at the memory.

“Hedonists, the both of you!”

Iskall released his cock and leaned back, allowing Grian to shuffle forward so he was between Mumbo’s legs. Grian carefully positioned his chest, leaning on Mumbo’s thighs to help support his arms, and cupped his breasts, sliding the well-lubed cock between them. Mumbo gasped, propping himself up on his elbows so he could watch better. 

“See, Mumbo,” Grian grinned cheekily, “now you can fuck my tits properly.”

Mumbo nodded, biting his lip. Iskall appeared beside him, having taken off his clothes while they had been distracted. He tugged Mumbo’s shirt up, exposing his slim waist and running a hand from his stomach to his chest. Iskall pressed open-mouthed kisses along Mumbo’s jaw, whispering something to him that made the other man shiver. 

Grian dipped his chin and opened his mouth, sucking on the head each time it slid through his tits. Mumbo’s answering moan sending a curl of warmth through his chest. After only a couple of minutes he felt Mumbo’s legs tensing and he doubled his efforts, arching his back to get the best angle.

“Grian! I’m gonna -” he heard Mumbo call out, so he took his cock in his mouth and let him cum, swallowing it down. Some leaked out of his mouth, mingling with his saliva and dripping onto his breasts. Grian sucked in a breath and coughed, wiping his mouth with the back of his hand as Mumbo recovered, the stamina potion doing its work - his cock barely softening before it was back.

They exchanged smiles, Mumbo helping Grian up the bed so they could kiss, soft and sweet. Iskall cleared his throat, getting their attention. 

“Sorry, Iskall. Hey darling,” Mumbo tucked a lock of hair behind his ear, “be a dear and give him a hand? That’s a good boy.”

Grian allowed himself to be turned, his arms wrapping around Iskall’s neck while he batted his eyelashes slyly up at him. Iskall’s hand drifted down and toyed with his pubic hair, eyes questioning.

“Green,” Grian told him, pushing his hips up to meet the touch, “please fuck me? I’ll be so good for you, Iskall.”

The other man hummed, fingers spreading him, and he felt cold wetness touch his skin, Iskall’s hand once more lubed up. He didn’t have to wait long for the first finger to enter him. Grian’s mouth fell open, his legs spreading to allow his boyfriend more access, tangling his own hands in Iskall’s hair.

“Yes,” he gasped, “more.”

A second finger quickly followed, sinking into his wet heat easily. They curled, pressing against his walls and stretching him as he panted. He groaned, wanting more. He pressed himself against Iskall, hips twitching in small thrusts as he tried to fuck himself on his fingers.

“More, more! Iskall, please! Please fuck me! I need you inside me! Please!”

The fingers withdrew frustratingly slow, drawing a whine from Grian when Iskall gently laid him down on his back before kneeling between his legs. His cock nudged against his thigh, smearing pre-cum along his skin. Grian clutched at Iskall’s arms, staring up at him.

“Please,” he pleaded, “I’m so empty. I’ve been a good boy haven’t I? I can take you so good, Iskall. Iskall, Iskall! Fuck me ple -”

He broke off as Iskall pressed inside, lube and his own slick letting the cock slide in easily. He groaned, wiggling his hips into a more comfortable position as Iskall’s hands came up to his breasts, cupping and kneading them. It was almost funny how much Iskall was obsessed with his boobs.

Grian brought his legs up and hooked them around Iskall’s waist, pulling him in as deep as he could go. He also braced his arms against the wall and nodded, signalling for him to start moving. As Iskall pulled out he drew a soft moan from Grian, slamming back in with a force that caused the sound to break, chopping it into short gasps of pleasure with each thrust. 

Iskall fucked him without pause, their hips meeting with sharp slaps of skin on skin, Grian’s head back and mouth open. It felt so good, but not enough for him. Iskall chased his own pleasure first, stiffening with a quick inhale as he came, resting for only a moment before he continued. Grian let go of the wall to clutch at Iskall’s hands on his chest, crying out.

“More!”

The other man gently pried his hands off his boobs and tucked them under Grian’s back, holding him close as he rolled them, positioning Grian on top. Grian ground down on his cock, taking him deeper, but it still wasn’t enough for him. He needed  _ more _ .

“Mumbo,” he called, voice quivering.

He looked over at Mumbo who was lounging next to the pillows, blush dusting his cheeks as he watched his boyfriends go at it. He blinked up at Grian, gaze slightly dazed as he stroked his dick. Grian reached for him, moaning as the cock inside him shifted.

“I need you,” he begged, “please. It’s not enough, I need you inside me - both of you, please!”

He leaned forward, pressing flat against Iskall, one hand grabbing his ass and spreading it. He babbled pleas against Iskall’s chest, desperate for his boyfriends to fill him. 

Grian felt hands rest across his back as Mumbo shuffled closer. He could barely see through his haze of lust, but he looked concerned.

“Grian, are you sure?” Mumbo asked, hesitant, “we’ve never done that before.”

“Nn,” he huffed, “I need it, please. I have two holes now and they both need filling, please!”

He clenched, hearing Iskall’s moan deep in his chest, and shivered.

“Dammit Mumbo,” Iskall growled, “just do it!”

Grian heard a faint click and then a lubed finger was pressing into him with a faint burn. A long sigh dragged out of him as he was stretched, a second and third finger being added as he loosened up. 

“Come on,” he rolled his hips, “fuck me!”

The fingers withdrew and were replaced by the blunt head of Mumbo’s cock, giving him a second to prepare before he too was filling him. 

Grian keened, the breath being driven out of his body as he was stuffed full, finally satisfied. 

“F-fuck, Iskall,” Mumbo swore, fingertips digging into Grian’s hips, “I can feel your dick inside him.”

Iskall nodded, panting. His hands smoothed over Grian’s hair, over his shoulders, down his back, and then gripped Mumbo’s wrists, the two of them now holding onto Grian steadily. 

“C’mon sweetheart,” Iskall urged, “be a good boy and fuck yourself on us. You can do it.”

Grian propped himself up weakly, hands on Iskall’s chest, and began to thrust. Caught between them he could barely move, but he could roll his hips and clench his pussy and ass, Mumbo and Iskall both letting out noises of pleasure. Rewarded by that, Grian drew himself up, gaining more room for movement. He was unaware of his own loud and broken moans filling the room.

He could feel semen from Iskall’s previous load dripping down his thighs.

The trio’s hot breath clouded the space, sweat dripping from their faces and down their backs. It was a good thing Scar’s base was across the lake, or else he might have heard more than he wanted too. 

Mumbo suddenly shouted, fingers twisting into a vice-grip on Grian’s skin as he thrust deep into Grian’s ass. His body shuddered, and Grian could feel the cum filling him, his mouth opening wide at the sensation. A hand hooked around his front and began to rub circles around his clit. 

Grian’s voice called out higher and higher, Mumbo’s breath tickling his ear as he encouraged him along.

“Cum for us, Grian.” 

He drove down on Iskall’s cock, wailing as his climax took him in its grip, hearing Iskall curse faintly as he finished in him again. 

Grian’s chest heaved as he sucked in air, blowing it out in great gusts as he rode his orgasm out, barely feeling the others’ touches as he was lost in the feeling. His body jerked as it trailed off, leaving him without strength as he collapsed back into Mumbo, spent.

He slowly became aware of hands in his hair and on his thighs, grounding him as they all caught their breaths. He blinked blearily down at Iskall, his boyfriend smiling fondly up at him, but there was a touch of a wince in his expression. Grian realized they were still inside him, and it was probably starting to get a little uncomfortable. He listed to the side, allowing his boyfriends to set him down with soothing murmurs and pull out as gently as possible. 

He hummed, content, as arms wrapped around him. He was sated and safe, ready for a nap between the two people he loved most in the world.

The mattress creaked beneath him, and Grian cracked an eye open and whined as the warmth against his back pulled away. 

“Shhhh,” Mumbo shushed, “I’m just going to brush my teeth.”

“What? Why? You never normally do that after sex,” Iskall hissed.

“Yes I do! I do it every time - I can’t believe you hadn’t noticed!”

Iskall scoffed and Grian hid his grin against the others chest.

“And - and this time,” Mumbo defended, “I have a  _ mustache _ -”

“And standards,” Grian interrupted, rolling onto his back with a chuckle. He frowned and covered his belly with his hands. “Oh my god, I feel so  _ full _ . You two came a lot.”

Iskall laughed as Mumbo buried his face in his hands, face going bright red. 

“Come on, Iskall,” he sat up slowly on trembling arms, “I think we all need to do a little cleaning up.”

Two pairs of hands helped him stand, and together they made their way to Grian’s bathroom.

**Author's Note:**

> ... and then they fucked in the shower but this does not need a part three so you can use your imagination for that!


End file.
